This invention relates to fluid dispensers in general, and more particularly to an actuator for actuating a dispensing pump that pressurizes air during a pumping cycle and introduces the pressurized air into the fluid passage of the actuator during the cycle to improve fluid atomization and/or after the cycle to clean out the passage.
Fluid dispensers are frequently fitted with dispensing pumps for dispensing a fluid product from the container of the dispenser. One type of dispensing pump for which the present invention is particularly well adapted is a modular pump, which is a self-contained structure that may be assembled and shipped separately from the rest of the dispenser.
A dispensing pump is typically fitted with an actuator, which is mounted on the stem of the dispensing pump. The actuator transmits force applied by the user to the pump stem to depress the stem and thereby dispense the fluid. The actuator contains a fluid passage to conduct the dispensed fluid from the pump stem to a discharge orifice that atomizes and discharges the fluid.
Two problems exist with current actuator and dispensing pump designs: the fluid passage can become clogged with fluid residue and the fluid can be inadequately atomized. Some fluid products dispensed by dispensing pumps, such as anti-perspirants and hair spray, are particularly susceptible to forming residues in actuator fluid passages if allowed to dry in the passage. Thus, an actuator on a hair spray or anti-perspirant dispenser that is not used every day can become clogged by residue, preventing the fluid dispenser from dispensing the fluid product. The user must then remove the actuator from the pump stem and immerse it in warm water to attempt to dissolve the clogging residue. As this step is often ineffective, the entire dispenser can be rendered useless.
The second problem with current actuator and dispensing pump designs is that the fluid, particularly consumer products such as anti-perspirants, may be inadequately atomized. The finer the mist that is produced by the fluid dispenser, the dryer the sensation when the mist contacts the user's skin. Dispensing pumps can be less effective than other dispensers, such as aerosols, in atomizing the fluid.
One approach to these problems is disclosed in U.S. Pat. No. 4,057,176 to Horvath. Horvath discloses a pump in which depression of the actuator pressurizes liquid to be dispensed in a central pump cylinder and pressurizes air in a concentric annular chamber formed between the actuator and the integral pump and screw cap assembly. The usual breakup insert is not provided so the pressurized liquid and air must be forced through pressure responsive seals into a mixing chamber, where the pressurized air atomizes the fluid.
The pump of Horvath suffers from several disadvantages. The mechanism is complex, involving many intricately-formed parts. More significantly, by forming the air chamber between the actuator and the integral pump and cap assembly, the disclosed mechanism for aerating the fluid cannot be used with other dispensing pumps or mounting caps.
Thus, it is evident that there is a need for a self-contained actuator that prevents clogging of the actuator fluid passage, improves atomization of the dispensed fluid, and can be used with any type of dispensing pump.